This invention relates generally to a water control system and, more particularly, to a system for modulating flood flow in a watercourse.
Dam structures are used extensively to raise the level of a stream or river and thereby produce an elevated head of water which can be used for irrigation or industrial purposes. In some cases, such dam structures include gates that are normally held in an upright closed position but pivot to an open position when the level of a retained water body exceeds a predetermined height. Water gates of this type are operated either manually or by manually initiated electrical or hydraulic actuators controlled by an operator monitoring the level of the water body being retained.
To eliminate the requirement for manual supervision, there have been proposed various types of balanced water gates which open or close automatically in response to the level of the retained water body. Examples of balanced gates are disclosed, for example, in U.S. Pat. Nos. 803,072; 1,039,072 and 4,073,147. Most such automatic gates are designed for operation in response to changes in hydraulic pressure produced by rising and falling levels of the water body. Operational problems of hydraulically operated, balanced gates result from time induced deterioration of bias mechanisms employed for balance control. Also, operation of balanced gates can be adversely effected by accummulated upstream debris or by the downstream deposition of sand, clay and rocks. Also known are gates automatically controlled by float type water level detectors. However, the performance of float operated gates frequently is adversely effected by debris and water currents existing near proximately located float detector devices. Erratic operation of such prior gates can cause significant changes in downstream water flow rates which adversely affect conservation and wildlife interests.
The object of this invention, therefore, is to provide an improved flood flow modulator system.